Zap OccInfo on case binders during StgCse #14895 (closed) #24233 (closed)
StgCse can revive dead binders:
case foo of dead { Foo x y -> Foo x y; ... }
===>
case foo of dead { Foo x y -> dead; ... } -- dead is no longer dead
So we must zap occurrence information on case binders.
Fix #14895 (closed) and #24233 (closed)